1. Field of the Invention
The present invention relates to a device for leveling soil in orchards and the like and more particularly to such a device adapted to be towed behind a tractor or the like, the device providing a first soil engaging blade assembly adapted to engage soil and to direct such soil into an elongated pile disposed longitudinally of the path of travel of the tractor and a second blade member adapted to engage the soil so deposited and to substantially evenly disperse such soil in a substantially common plane.
2. Description of the Prior Art
The use of devices for the leveling or other grading of earth surfaces has long been known. Representative of such devices are earth levelers adapted to be moved under their own power or by towing along a predetermined course desired to be graded. Such devices commonly provide a single blade having an earth engaging portion, the blade being mounted on the device whereby the blade engages the earth to be leveled at an angle substantially oblique to the path of travel of the device. Portions of the soil so engaged tend to be moved across the blade surface substantially transversely to the line of travel in a direction from the leading portion of the blade toward the trailing portion.
While conventional earth leveling devices have proved satisfactory in varying degrees for their intended purposes, they are attended by a number of deficiencies and drawbacks. For instance, it is often seen that the amount of soil or the like carried toward the trailing portion of the blade by the movement forwardly of the device is either too great or too little to result in an even dispersal of the soil. It is an accepted principle that in the leveling of soil and the like it is desirable to have a combination of removal of dirt from those areas that are relatively built-up and a deposit of soil on those areas which are rutted or relatively shallower. However, when a device having a single oblique blade member is caused to move along a path in which the relatively shallow soil is that over which the leading edge passes, and the relatively built-up soil is that engaged by the trailing edge, it is found that the blade must be in to a greater depth than is desirable to permit the evening of the soil in a single pass. If the leading edge is not adjusted downwardly to bring it into engagement with the soil, but rather is permitted to ride above, and out of engagement with, the shallow portions, the shallow portions will not be relatively filled in or brought into a level disposition relative to the previously built-up areas because no dirt will be carried along the blade to that portion of the soil. Thus, it is often found that a single blade device necessitates two or more passes along a single row or course to be leveled, in order to effect a substantially horizontal leveling of the entire desired course.
In almond orchards and the like in which it is common to have the trees thereof planted in substantially parallel rows atop raised berms to define courses or paths therebetween, it is desirable, for irrigation purposes, to have as level a course between the berms as possible. Use of a conventional, singlebladed leveling device to remove ruts and otherwise level the course between the two berms often results in the deposit of excessive amounts of soil on the berm nearest the trailing edge of the oblique blade, whereby the course between the berms is caused to be bounded by asymmetrical borders.
Of further concern in many areas in which land leveling orchards or the like is desirable, is the inability of many conventional devices to provide means for maintaining the blade thereof in a substantially horizontal attitude, regardless of the degree of transverse pitch of the course over which the device is caused to travel. Those devices providing automated leveling generally do so by causing the angle of the blade itself to change relatively to the frame on which it is carried.
Still further, a problem common to many conventional land leveling devices is that the blade portions thereof are of a single, predetermined, non-adjustable length. Thus, a given device might have limited or no utility in a number of work environments due to the blade thereof being too long to fit between the berms, for instance, without damage thereto during the leveling operation; or too short efficiently to level the entire course between the berms, thus necessitating multiple, repeated passes to accomplish asemblance of leveling.
Therefore, it has long been known that it would be desirable to have a land leveling device which is adapted for use in myriad land leveling operations and environments wherein such device is capable of substantially evenly dispersing the surface soil of a desired course in a single pass and wherein the device is adjustable for use in a wide variety of courses of varying widths. Moreover, it has long been known that it would be desirable to have such a land leveling device which is adapted automatically to maintain the blade thereof in a substantially horizontal attitude virtually continuously during the operation thereof.